The practical use of the directed self-assembly lithography technique utilizing a property that a block copolymer is self-assembled is discussed (for example, Patent Documents 1 and 2 and Non-Patent Document 1). In the directed self-assembly lithography technique, first, for example, a solution of a block copolymer containing an A polymer chain and a B polymer chain is applied to a substrate, whereby a thin film of the block copolymer is formed.
Then, when the substrate is heated, the A polymer chain and the B polymer chain mutually randomly solid-dissolve in the thin film undergo phase separation to form A polymer regions and B polymer regions which are regularly arrayed.
The phase separation of the block copolymer is realized by A polymers and B polymers fluidized by heating and the A polymers gathering together and the B polymers gathering together.